how to make previous snapshots of a gif transparent in python

I am making a gif using figures in python. At the moment my code disappears previous snapshots. I have three figures to make the gif. The following is my code:

import imageio
files = [f'fig_{i}.jpg' for i in range(1,4)]
images = []
for name in files:
    images.append(imageio.imread(name))
imageio.mimsave('output_gif.gif', images, 'GIF', duration = 1)

This code gives the following gif:

But I want to see previous figures in each snapshot but a figure with alpha = 0.5. I mean the first snapshot should show the first figure, then in the next one the new figure pops up while the old one gets transpare. An in the last snapshot first two figure should be transparent while the new coming is poping up.

These are also three figures I used for making the gif:

I very much appreciate your help.